Cardiac arrest, compressions underway, nursing unable to obtain access. It's time for epi. You turn to the intern next to you, and ask him to grab the IO kit, and place an IO quickly for central access. He grabs the kit, attaches the drill bit and stares at the leg. Not only has he attached the wrong size drill bit, he clearly has no idea what to do next.
6 months into residency, I would say less than 10% of residents or PAs have placed an IO. Usually the more senior residents and staff are at the airway or foot of the bed running the code so it makes sense the task often falls to more junior staff. It's a 30 second procedure, but I often find myself waiting minutes for access, unless I leave my role and do it myself.
Two questions hesitant users of an IO often ask me; where to do I put it? which size drill do I use?
There are lots of resources for IO placement locations online, but I have a strong preference. During a code, I expect you to stay away from the airway or chest unless you are intubating/bagging or doing chest compressions or attaching pads. That leaves the tibial plateau as the go to place. You are out of the way from other important tasks, so you have clear space to work.
Here's the idiot's how-to version: expose the leg, track down from the kneecap along the medial side of the leg, until you feel a flat surface of bone, triangular in nature, with the medial surface being the largest flat section of bone. You can palpate for the tip of the triange, the most anterior surface. If you are thin, you can literally exposure the flat surface of your own tibia. Check it on yourself and decide where you would want to put an IO in yourself.
How to Place an IO for Tibial Access (IO Trainer)
Now for the second question, size of the needle. You don't need an instruction guide for this one. Your goal it to put the tip of the needle into the center of the bone. You have to clear any soft tissue, get to the bone, and through it with at least 1cm of margin. When it doubt get a longer drill bit, and choke up on it. There's nothing worse than putting in a medium IO drill bit into a obese leg, hubbing it, the tip is just under the bone, and after the first use it slides out of the bone. Or the flip side, putting a long bit through and through someone's leg. Yes, I have watched people do both.
The last thing that you need to do, is practice. I ask so many people why they hesitate, and the answer is almost always "because I've never done it before". There must be something unnerving about drilling into a human being, because so few 1st timers step and try in a reasonable time period. These same learners however, rapidly perform the task the second time I ask them to do it.
So get yourself an IO trainer, and drill it into oblivion. You will be far more comfortable with the feel of the drill, the give of bone, and pressing through the skin and fat. Drill into various locations, at different angle, move around the table drilling from different positions. Practice first, and be prepared when someone's life depends on it.